This invention relates to safety helmets used during high speed racing events with vehicles including motorcycles and race cars. At high speeds buffeting of the helmets occurs, which has required special strapping and tie-down features, so as to reduce movements of the helmets and to prevent their displacement on or from the wearer's head. The buffeting which has occured is characterized by irregular lift action as a result of aerodynamics, and resulting in jerking or jiggling motions that turn the helmet into unpredictable positions, it being a general object of this invention to provide aerodynamic features on the helmet per se, features that reduce and/or eliminate undesirable lift and detremental buffeting.
Safety helemts of the type under consideration are comprised of a shell of lightweight high impact resistant material such as a carbon fiber Kevlar.RTM. fiberglass composite material. It is customary to line the shell with a cushioning liner of shock absorbent material such as a molded inner shell of styrofoam interfaced with the interior of the outer shell and shaped to fit the head contours of the wearer. These helmets are of a so called "full face" design, completely shielding the face of the wearer, and with a transparent window widened for complete peripheral vision. In practice, the window is made of a substantially thick (0.125 inc.) Lexan.RTM. shield. As thus far described, the helmet covers the head of the wearer, with adequate ventilation betweath the wearer's chin and around the wearer's neck. However, ventilation over the forehead and scalp of the wearer tends to be inhibited, and to this end it is common practice to provide vent openings to induce flow-through ventilation. The aforesaid inner liner occupies the space between the helmet shell and the wearer's head and is provided with ducts that distribute air flow as may be required. It is an object of this invention to provide a helmet of the above description with air ducting in the liner and through the helmet shell to enhance the aerodynamics of the helmet, whereby undesirable lift and/or detremental buffeting is reduced and/or eliminated.
Present day open cockpit race cars travel at speeds up to and exceeding 200 m.p.h., at which speeds the air moving over the vehicle and its driver is quite turbulent. Firstly, the air flow over the cockpit is initially turbulent, which causes buffeting of the driver's helmet. And accordingly, the air flow over the helmet per se remains turbulent, which aggravates buffeting of the driver's helmet. The vehicle turbulence is attenuated as best as possible in the vehicle design, but buffeting of the prior art helmets persists. However, helmet buffeting is further attenuated by the present invention, it being an object of this invention to provide a stall strip in conjunction with a supply of interior air from between the helmet shell and the wearer's head, to reduce and/or eliminate helmet lift and buffeting. A characteristic feature of this invention is the stall strips that protrude from the helmet surface contour to control turbulence over the re-entry portion of the helmet, as will be described.